* Scientist jailed in 2004, denied espionage charges
* Describes himself as a political prisoner
Russian scientist Valentin Danilov walked free on parole on Saturday after serving eight years of a 14-year sentence on charges of spying for China during President Vladimir Putin's first term.
Danilov, 66, said shortly after his release in the Siberian city of Krasnoyarsk that he had regarded himself as a political prisoner because the information he passed on was declassified.
"I would really appreciate it if somebody finally told me what state secret I sold," he said.
Danilov smiled, joked and laughed with reporters. Asked about his health, the physicist said: "I'm fine. Otherwise I wouldn't be here."
Human rights activists saw Danilov's case as an example of the Kremlin's use of the courts against opponents although Putin, who was president from 2000 until 2008 and began a third term in May, has denied influencing the courts.
Danilov was sentenced in 2004 but had already been held in detention before and during his trial. A Krasnoyarsk court granted him parole earlier this month.
First arrested in 2001, he was a researcher at Krasnoyarsk State University. He admitted selling information about satellite technology to a Chinese company but said the information had already been available from public sources.
An initial decision to acquit him was overturned and he was sentenced in a second trial.
Danilov's case was one of several during Putin's first spell as president that were seen by opponents as an attempt to intimidate academics with ties to other countries.